We’ve covered paint-on solar cells previously – now boffins at Rice University have created spray-on batteries; a development easily adapted to current commercial processes and one that could revolutionise the battery industry.
Batteries created using the paint-on process will allow for a plethora of new design and integration possibilities for storage devices says Pulickel Ajayan, a Professor in mechanical engineering, materials science and chemistry at Rice.
The battery consists of five layers – two current collectors, a cathode, an anode and a polymer separator – each of which are sprayed on.
According to a press release from the University, the first layer is a positive current collector made of high purity single-wall carbon nanotubes with carbon black particles dispersed in N-methylpyrrolidone.
The second is the cathode; made with lithium cobalt oxide, carbon and ultra-fine graphite powder mixed in a binder solution. The third is a polymer separator paint containing Kynar Flex resin, Poly methyl methacrylate and silicon dioxide dispersed in a solvent.
The fourth layer acts as the anode and consists of lithium titanium oxide and ultra-fine graphite in a binder solution. The final layer is the negative current collector, made with a conductive copper paint already commercially available that is diluted with ethanol.
In an experiment, a battery bank was created using bathroom tiles as a substrate. One battery was topped with a solar cell and using a laboratory light as an energy source, once fully charged the battery bank powered 40 light-emitting diodes (LEDs) for six hours. After 60 charge and discharge cycles, the paint-on batteries only experienced only a small amount of storage capacity loss.
The researchers have filed for a patent on their invention and will continue to refine the technology and associated processes. A complete technical description of the spray-on battery appears in Nature.com’s Scientific Reports.
The researchers see the potential of integrating their paintable battery technology with paint-on solar cells. Some of the spray/paint-on solar cell technology we’ve covered in the past includes Sun-Believable and SolarWindow.
